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Aviation History
1918
1918 - 0027.PDF
JANUARY 3, 1918. £353 INTERNATIONAL AIRCRAFT STANDARDS. Continued from page 1368, December 27th, 1917.) 3-VS—Specifications for Sheet Copper. GENERAL.—1. The general specifications, IGT, shall form,according to their applicability, a part of these specifications. MATERIAL.—2. (a) The copper used shall be lake orlectrolytic, conforming with the T.A.S.B. specifications 2N2, and shall be hot rolled or hot rolled and finished b ' coldrolling and annealing or by final cold rolling as required. (b) Chemical analysis shall not be required ; but samplesmay be taken for analysis to check the quality of the material used, in which case the sheet, after being thoroughly cleanedfrom all oxide and dirt, must show a purity of 99.85 percent, copper plus silver. WORKMANSHIP AND FINISH.—3. The material shall beclean, smooth, or uniform colour, and shall be free from all injurious defects. PHYSICAL PEOPERTIES AND TESTS.—4. (a) The sheetsshall have the following physical properties : TENSILE TESTS. Grade. Soft . . Hard Minimum elongation in z inches (50 .8 mm.)Minimum tensile strength. 30,000 pounds per square inch (21.00 kg./mm.-) . . .. . . . . 25 per cent. 35,000 pounds per square inch (24.61 kg. /mm.-) T 8 per cent. thick are not(b) Sheets less than 0.072 ins. (r.83 mm.) subject to physical test. (c) The tensile strength of hard-rolled thin sheets will be considerably more and the elongation considerably less than that indicated in the above table. Bend Test.—(d) The soft sheets must withstand bending flat on themselves in any direction without cracking. SELECTION OF TEST SPECIMENS.—5. One test shall be taken from each lot of 500 lbs. (226.8 kg.) or less. DIMENSIONS AND TOLERANCES.—6. (a) The weight or thickness shall not vary more than 5 per cent, from that specified. Thickness shall be specified in decimals of an inch or millimetre and shall correspond to the ordinary gauge numbers. (b) For wide sheets or plates above 48 ins. (1,219 mm.), to and including 60 ins. (1,524 mm.), a tolerance of 5 per cent, over or 7 per cent, under gauge or weight will be allowed. (c) For extra wide sheets or plates above 60 ins. (1,524 mm.) in width the tolerance may be 5 per cent, over or 8 per cent, under gauge or weight. (d) For the purpose of calculating weights, etc., the specific gravity of copper shall be taken as S.80 at 20 deg. C, or 0.3212 lbs. per cubic inch (8.89 g. per cm.3). DELIVERY, PACKING, AND SHIPPING.—7. (a) When orders call for 12-ft. (3.66-m.) lengths, the following tolerances as to lengths will be allowed, but in no case shall the aggregate amount of these short lengths exceed 40 per cent. : 40 per cent, may be 10 ft. (3.05 metres) or over. 30 per cent, may be 8 ft. (2,44 metres) to 10 ft. (3.05 metres). 20 per cent, may be 6 ft. (1.83 metres) to 8 ft. (2 .44 metres). 10 per cent, may be 4 ft. (1.22 metres) to 6 it. (1.83 metres). When orders call for 10-ft. (3.05-m.) lengths, the following-tolerances as to lengths will be allowed, but in no case shall the aggregate amount of these short lengths exceed 40 per cent. : 40 per cent, may be 8 ft. (2 .44 metres) or over. 30 per cent, may be 6 ft. (1.83 metres) to 8 ft. (2.44 metres). 20 per cent, may be 4 ft. (1.22 metres) to 6 ft. (1.83 metres). 10 per cent, may be 2 ft. (o .61 metre) to 4 ft. (1.22 metres). When orders call for 8-ft. (2.44-m.) lengths, the followingtolerances as to lengths will be allowed, but in no case shall the aggregate amount of these short lengths exceed 30 per cent. : 30 per cent, may be 6 ft. (1.83 metres) or over. 20 per cent, may be 4 ft. (i .22 metres) to 6 ft. (1.83 metres). 10 per cent, may be 2 ft. (o .61 metre) to 4 ft. (1.22 metres). When orders call for 6-ft. (1.83-m.) lengths, the followingtolerances as to lengths will be allowed, but in no case shall the aggregate amount of these short lengths exceed 20 percent. : 20 per ecnt. may be 4 ft. (1.22 metres) or over. 10 per cent, may be 2 ft. (o .61 metre) to 4 ft. (1.22 metres). (b) Below 1 in. (25.4 mm.) wide sheet copper roay befurnished in rolls or coils, in which case it will be cold rolled or cold rolled and annealed. 3./V9—Specification for Phosphor-Bronze Strip. GENERAL.—1. The general specifications, 1G1, shall form,according to their applicability, a part of these specifications. USE.—2. This strip to be used for springs. MATERIAL.— •,. (a) The bronze shall conform <o (hefollowing chemical composition : Copper Zinc, maximum Iron, maximum Phosphorus, maximum Tin Per cent. 91 to 93 0.20 O . 10 O.IS Remainder. (d) Drillings or clippings for analysis shall be taken from both ends of the coil sampled and shall be free from all surface oxide or dirt. MANUFACTURE.—4. a) The bronze shall be crucible melted from lake or electrolytic copper, according to I.A.S.B. speci- fication 2N2 and best Straits' or equivalent tin and deoxidised with phosphorus. (b) No scrap shall be used except such as may accumulate in the manufacturer's plants from material of the same com- position and of their own make. (c) All strip shall be rolled to spring temper unless otherwise ordered. WORKMANSHIP AND FINISH.—5. The surface of the strip shall be clean and smooth, and it shall be free from injurious defects such as blisters, slivers, or dirt embedded in the surface. PHYSICAL PROPERTIES AND TESTS.—6. Phosphor-bronze spring strip shall h;tve the following physical properties : Elongation in Tensile Strength. Yield Point. 2 ins. (TO .8 mm.). Minimum, 85,000 lbs. per sq. in. 65,000 lbs. per sq. in. 5 percent. (50.76 kg./mm-'.). (45.70 kg./mm-.). 20 per cent. Maximum, 115,000 Il>s. per sq. in. 95,000 lbs. per sq. in. (80.85 kg./mm'-'.). (66.70 kg.'mm'.). SELECTION OF TEST SPECIMENS.— 7. When shipments aremade in coils, a specimen from every tenth coil shall be taken for physical tests. When shipments are made in short lengths,a specimen will be taken from each case. DIMENSIONS AND TOLERANCES.—-8. The tolerancesallowed shall be as given in the following table : TOLERANCES. ENGLISH UNITS. American Wire Gauge (B. & S.). No. 8 to 14 No. 15 to 18 No. 10 to 24 No. 25 to 28 No. 29 to 32 American Wire Gauge (B. & S.). No. 8 to 14 No. 15 to 18 No. 19 to 24 No. 25 to 28 No. 29 to 32 Thickness, inches. o .1285 too.0641 0.0571 to 0.0403 0.0359 to o .0201 o .0179 to o.0126 o.0113 to 0.00S0 Less than 5 5 to 8 ins. wide ins. wide. ±0.0029 ±0.0033 ±0 .0025 ±0 .0029 ±0.0020 ±0.0024 ±0.0016 ±0.0020 ±0.0013 ±0.0017 Tolerance, inches. 8 88 to 11 ins. wide. ±0.0036 ±0.0033 ±0.0028 ±0.0024 ±0.0020 11 to 14 ins. wide. ±0.0040 ±0.0037 ±0.0032 ±0.0028 ±0.0024 METRIC UNITS. Tolerance, millimetres. Thickness, Less than 127 127 to 203 203 to 279 279 to 356 millimetres mm. wide. mm. wide. mm. wide. mm. wide. 3.264 to 1.628 ±0.074 ±0.084 ±0.091 ±0.102 i .450 to 1.024 ±0.064 ±0.074 ±0.084 ±0.094 0.912 too.511 ±0.051 ±0.061 ±0.071 ±0.081 0.455 to o .321 ±0.041 ±0.051 ±0.061 ±0.071 o.a86 to 0.202 ±0.033 ±0.043 ±0.051 ±0.061 DELIVERY, PACKING, AND SHIPPING.—9. (a) When orderscall for 12-ft. (3.66-m.) lengths, the following tolerances as to lengths will be allowed, but in no case shall the aggregateamount of these short lengths exceed 40 per cent. : 40 per cent, may be 10 ft. (3.05 metres) or over. 30 per cent.may be 8 ft. (2.44 metres) to TO ft. (3 20 per cent, may be 6 ft. (1.83 metres) to 8 ft. (2.44 metres), t b ft (t) t 6 ft (8 t) p y (3 ) (3.05 metres). . 10 per cent, may be 4 ft. (1.22 metres) to 6 ft. (1.83 metres). When orders call for 10-ft. (3.05-m.) lengths, the followingtolerances as to lengths will be allowed, but in no case shall the aggregate amount of these short lengths exceed 40 per cent. : 40 per cent, may be 8 ft. (2 .44 metres) or over. 30 per cent, may be 6 ft. (1.83 metres) to 8 ft. (2.44 metres). 20 per cent, may be 4 ft. (1.22 metres) to 6 ft. (1.83 metres). 10 per cent, may be 2 ft. (o .61 metres) to 4 ft. (1.22 metres). When orders call for 8-ft. (2.44-m.) lengths, the followingtolerances as to lengths will be allowed, but in no case shall the aggregate amount of these short lengths exceed 30 per cent. : 30 per cent, may be 6 ft. (1.83 metres) or over. 20 per cent, may be 4 ft. (1.22 metres) to 6 ft. (1. 83 metres). IO per cent, may be 2 ft. (o .61 metre) to 4 ft. (1.22 metres). When orders call for 6-ft. (1.83-m.) lengths, the followingtolerances as to lengths will be allowed, but in no case shall the aggregate amount of these short lengths exceed 20 per cent. : 20 per cent, may be 4 ft. (1.22 metres) or over. to per cent, may be 2 ft. (0.61 metre) to 4 It. (1.22 metres). (6) Coils shall not contain more than four lengths, andlengths shall be at least 10-ft (305 m.) long.
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